Incidence of SARS-CoV-2 infection in children shortly after ending zero-COVID-19 policy in China on December 7, 2022: a cross-sectional, multicenter, seroepidemiological study.

Background: China discontinued the zero-COVID-19 policy on December 7, 2022, and then COVID-19 surged mid-December 2022 through mid-January 2023. However, the actual incidence was unknown. This study aimed to estimate the incidence of SARS-CoV-2 infection in children shortly after ending the zero-COVID-19 policy. Methods: This multicenter cross-sectional study included 1,065 children aged 8 months to 12 years from seven hospitals at six regions across Jiangsu province, based on the convenience sampling, from February 10 to March 10, 2023. Group I comprised 324 children aged 8 months-2 years without COVID-19 vaccination, group II consisted of 338 preschool children aged 3-5 years with varied vaccination history, and group III contained 403 primary school children aged 6-12 years with mostly vaccinated. The COVID-19 vaccines were composed of inactivated SARS-CoV-2. In addition, 96 children's sera collected in 2014 were included as negative controls. IgG and IgM antibodies against nucleocapsid (N) and subunit 1 of spike (S1) of SARS-CoV-2 (anti-N/S1) were measured with commercial kits (YHLO Biotech, Shenzhen, China). Results: None of the 96 children (5.1 ± 3.5 years; 58.3% boys) in 2014 was positive for anti-N/S1 IgG or IgM. Of the 1,065 children (5.0 ± 3.5 years; 56.0% boys), 988 (92.8%) were anti-N/S1 IgG positive but none was anti-N/S1 IgM positive. The positive rate of anti-N/S1 IgG in Group I, II, and III was 90.4, 88.5, and 98.3%, respectively, with significantly higher in group III than in groups I and II (p < 0.0001). The median antibody titers in group III (381.61 AU/ml) were much higher than that in group I (38.34 AU/ml) and II (51.88 AU/ml; p < 0.0001). Conclusion: More than 90% children experienced SARS-CoV-2 infection shortly after ending zero-COVID-19 policy in China, much higher than estimated infections by other studies. The widespread SARS-CoV-2 infection in unvaccinated children should be influential on the policy of COVID-19 vaccination in children in the future.

Ready-to-implement low-carbon retrofit of coal-fired power plants in China: Optimal scenarios selection based on sludge and photovoltaic utilization.

Currently the flexible demand for high proportion penetration of renewable energy depends on coal-fired units (CFUs), and the large-scale phase-out of CFUs in a short time is not realistic in China. Due to urban expansion, approximately 458 Chinese coal-fired power plants (CFPPs) are now located in cities. Limited by space, urban CFUs face difficulty in becoming equipped with carbon capture and storage systems. This presents a sizeable challenge for the low-carbon transition of urban CFPPs and carbon neutral processes. Here, we present a ready-to-implement method to reduce the carbon emission of CFPPs in limited space: roof photovoltaic-assisted power generation combined with sludge co-combustion for coal-fired power generation systems (PVSCs). We also consider nonurban CFPPs with the method of roof photovoltaic-assisted power generation (PVs) only. Based on remaining life cycle analysis, we find that the PVSCs could save 28.47 Mt of coal, reduce CO2 emissions by 69.76 Mt, treat 125.70 Mt of sludge, and also generate 12.08 billion RMB worth of electricity revenue per year. In addition, our scenario analysis shows that PVSCs are more profitable when choosing an urban CFU with a remaining life of more than 12 years and while the sludge treatment subsidy is set at 100 RMB t-1. Under strict and lenient CFU decommissioning policies, CFUs with a remaining life of between 19 and 30 years and between 13 and 24 years should be selected for PVs, respectively. Thus, we conclude that PVSCs can not only generate economic benefits but also facilitate carbon reduction and solid waste treatment.

Case-based reasoning based on grey-relational theory for the optimization of boiler combustion systems.

Boiler combustion optimization is an important method to improve the flexibility of thermal power units and ensures the stability of unit operation. However, time-variability of boiler combustion systems and time-consuming optimization methods pose great challenges for the use of boiler combustion optimization techniques because many optimization methods cannot be used online in practical engineering due to time constraints. In this paper, we propose a case-based reasoning optimization method based on grey-relational theory (GR-CBR) for online optimization of a boiler combustion system. After the introduction of the proposed algorithm, we discuss the potential of applying the proposed GR-CBR optimization method to a boiler combustion system; a case study of an existing fossil fuel power plant is conducted to demonstrate the feasibility of the proposed method. A least-squares support vector machine (LS-SVM) model of the boiler combustion process is established by using the real-time operation data of a 350-MW coal-based power plant. Based on the model, a non-linear global optimization algorithm is proposed to obtain the optimal case base and real-time data mining and online optimization are used to achieve efficient and stable boiler combustion optimization. The results of combining offline optimization with online querying show that this approach is suitable for online real-time combustion optimization, and provides support for power plant operators for optimization and condition monitoring to improve boiler efficiency, reduce NOx emissions, and ensure stable and efficient operation of the power system.

Minimization of hepatitis B infection among children in Jiangsu, China, 12years after integration of hepatitis B vaccine into the expanded program on immunization.

BACKGROUND: China has integrated hepatitis B vaccine into the Expanded Program on Immunization since 2002. We aimed to survey the seroprevalence of and immunity to hepatitis B virus (HBV) in children born from 2002 to 2014 in Jiangsu, China. METHODS: Totally 3442 children (M:F=2072:1370) at the age of 7months to 12years (5.5±3.6), from five cities and rural areas across Jiangsu province, were enrolled. Blood samples were measured for HBV markers by ELISA and quantitative microparticle enzyme immunoassay. HBV DNA was tested by real-time PCR and S region was amplified by nested PCR. RESULTS: Twelve (0.35%) children were positive for hepatitis B surface antigen (HBsAg) and 34 (0.99%) were HBsAg negative and positive for antibody against hepatitis B core antigen (anti-HBc). Totally 2542 (73.85%) children had anti-HBs levels ⩾10mIU/ml and 535 (15.54%) with 2-9.9mIU/ml. All 12 HBsAg-positive children had detectable HBV DNA with a mean level of 6.1±1.7logIU/ml (3.3-8.1logIU/ml); 8 were genotype C and 4 were genotype B. No mutation was detected in the a determinant of HBsAg. HBV DNA was not detected in all the 34 children with positive anti-HBc and negative HBsAg. CONCLUSION: HBsAg prevalence among children in Jiangsu born after the introduction of universal vaccination against hepatitis B has significantly decreased. No mutation of S gene is associated with vaccine failure in the cohort of children.

[Quantong Recipe integrated with ureteroscopic laser lithotripsy for ureteral calculi].

BACKGROUND: Endoscopic surgery of Western medicine has developed rapidly in treating ureteral calculi while traditional Chinese medicine (TCM) therapy also has its advantage, thus the integrated traditional Chinese and Western medicine therapy may have an even better efficacy in dealing with this problem. OBJECTIVE: To observe the clinical effects of sequential therapy of Quantong Recipe, a compound traditional Chinese herbal medicine, combined with ureteroscopic laser lithotripsy on ureteral calculi. DESIGN, SETTING, PARTICIPANTS AND INTERVENTIONS: A total of 151 patients with ureteral calculi (stone diameter of 3 to 21 mm) from Department of Urology, Yueyang Hospital of Integrated Traditional Chinese and Western Medicine, Shanghai University of Traditional Chinese Medicine were included, of which 106 patients with stone diameter of 3 to 10 mm were treated with Quantong Recipe for the first two weeks. Twenty patients with unexpelled stones and 45 patients with stone diameter of more than 10 mm were treated with ureteroscopic laser lithotripsy. The 65 patients except one open operation were divided into regular treatment group (32 cases) and regular treatment combined with Quantong Recipe group (32 cases) after lithotripsy. The efficacy was assessed after one week. MAIN OUTCOME MEASURES: Cure rate in the patients with stone diameter of less than 10 mm after two-week Quantong Recipe treatment was calculated, and clearance rate in the patients with residual stone for ureteroscopic laser lithotripsy after one-week Quantong Recipe treatment was also observed. RESULTS: After taking Quantong Recipe for two weeks, the stones in 86 patients were completely discharged, and the stones in 6 patients were not completely discharged, but the unexpelled stones had moved down more than one segment of ureteral stenosis; the total response rate was 86.79% (92/106). The 64 patients with stones unexpelled or with stone diameter of more than 10 mm were treated with ureteroscopic laser lithotripsy, and the clearance rate of residual stone was 93.8% in regular treatment combined with Quantong Recipe group, and was 71.9% in regular treatment group, and there was a significant difference between the two groups (P<0.05). CONCLUSION: Sequential therapy of Quantong Recipe integrated with ureteroscopic laser lithotripsy demonstrates a significant advantage of integrated traditional Chinese and Western medicine therapy in treating ureteral calculi.

Enzyme-modified nanoporous gold-based electrochemical biosensors.

On the basis of the unique physical and chemical properties of nanoporous gold (NPG), which was obtained simply by dealloying Ag from Au/Ag alloy, an attempt was made in the present study to develop NPG-based electrochemical biosensors. The NPG-modified glassy carbon electrode (NPG/GCE) exhibited high-electrocatalytic activity toward the oxidation of nicotinamide adenine dinucleotide (NADH) and hydrogen peroxide (H(2)O(2)), which resulted in a remarkable decrease in the overpotential of NADH and H(2)O(2) electro-oxidation when compared with the gold sheet electrode. The high density of edge-plane-like defective sites and large specific surface area of NPG should be responsible for the electrocatalytic behavior. Such electrocatalytic behavior of the NPG/GCE permitted effective low-potential amperometric biosensing of ethanol or glucose via the incorporation of alcohol dehydrogenase (ADH) or glucose oxidase (GOD) within the three-dimensional matrix of NPG. The ADH- and GOD-modified NPG-based biosensors showed good analytical performance for biosensing ethanol and glucose due to the clean, reproducible and uniformly distributed microstructure of NPG. The stabilization effect of NPG on the incorporated enzymes also made the constructed biosensors very stable. After 1 month storage at 4 degrees C, the ADH- and GOD-based biosensors lost only 5.0% and 4.2% of the original current response. All these indicated that NPG was a promising electrode material for biosensors construction.

Immobilization of lignin peroxidase on nanoporous gold: enzymatic properties and in situ release of H2O2 by co-immobilized glucose oxidase.

Immobilization of enzymes on porous inorganic materials is very important for biocatalysis and biotransformation. In this paper, nanoporous gold (NPG) was used as a support for lignin peroxidase (LiP) immobilization. NPG with a pore size of 40-50 nm was prepared by dealloying Au/Ag alloy (50:50 wt%) for 17 h. By incubation with LiP aqueous solution, LiP was successfully immobilized on NPG. The optimal temperature of the immobilized LiP was ca. 40, 10 degrees C higher than that of free LiP. After 2h incubation at 45 degrees C, 55% of the initial activity of the immobilized LiP was still retained while the free LiP was completely deactivated. In addition, a high and sustainable LiP activity was achieved via in situ release of H(2)O(2) by a co-immobilized glucose oxidase. The present co-immobilization system was demonstrated to be very effective for LiP-mediated dye decolourization.

A novel nanoporous gold modified electrode for the selective determination of dopamine in the presence of ascorbic acid.

The electrochemical detection of dopamine (DA) at conventional solid electrodes was interfered by the coexisted ascorbic acid (AA). To circumvent this problem, many modified electrodes were tried. In this paper, an attempt was made to use nanoporous gold (NPG) as modifying materials. The NPGs with different pore sizes were prepared simply by dealloying Ag from Au/Ag alloy with concentrated nitric acid. The glassy carbon electrode (GCE) based modified electrode was fabricated by simply affixing the NPG film on the surface of a GCE. The electrochemical behaviors of AA and DA at the modified electrode were studied. The results indicated that the NPG/GCE exhibited substantial enhancement in electrochemical sensitivity for DA and AA due to its large surface area. Results also showed that the oxidation of AA at the electrode was a diffusion-controlled process, but for DA it was an adsorption-controlled process. This result, together with the different anodic peak potentials of the two species, made it possible the selective determination of DA in the presence of AA. Due to the interaction of the amino group of DA with the surface of nanoscale gold, DA could be accumulated on the NPG/GCE, while AA could not. This permitted the coexistence of large amount of AA. When differential pulse voltammetry (DPV) was used, a submicrolevel of DA could be detected in the millimolar level of AA with a detection limit of 17nM at a signal-to-noise ratio of 3. In a word, the modified electrode showed good sensitivity, selectivity and reproducibility.

Catalytic activities of fungal oxidases in hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate-based microemulsion.

For hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF(6)]), an H(2)O-in-[BMIM][PF(6)] microemulsion could be formed in the presence of nonionic surfactant Triton X-100 (TX-100). In such a medium, both lignin peroxidase (LiP) and laccase could express their catalytic activity with the optimum molar ratio of H(2)O to TX-100 at 8.0 for LiP and >20 for laccase, and the optimum pH values at 3.2 for LiP and 4.2 for laccase, respectively. As compared with pure or water saturated [BMIM][PF(6)], in which the two oxidases had negligible catalytic activity due to the strong inactivating effect of [BMIM][PF(6)] on both enzymes, the use of the [BMIM][PF(6)]-based microemulsion had some advantages. Not only the catalytic activities of both fungal oxidases greatly enhanced, but also the apparent viscosity of the medium decreased.